Add sdxl controlnet reference community pipeline (#9893)
* Add reference_attn & reference_adain support for sdxl with other controlnet
* Update README.md
* Update README.md by replacing human example with a cat one
Replace human example with a cat one
* Replace default human example with a cat one
* Use example images from huggingface documentation-images repository
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Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>
